High-frequency oscillations

[8][9] In hippocampus, this fast neuronal activity is effect of the population synchronous spiking of pyramidal cells in the CA3 region and dendritic layer of the CA1, which give rise to a characteristic oscillation pattern (see more in sharp waves and ripples).

[10] The HFO occurrence during memory task (encoding and recalling images) was also reported in human patients from intracranial recordings in primary visual, limbic and higher order cortical areas.

[15] Interestingly, higher HFO amplitudes (between 400 and 800 Hz) after nerve stimulation were also reported in the EEG signal of healthy football and racquet sports players.

[26] These NMDA receptor dependent fast oscillations were detected in different brain areas including hippocampus,[29] nucleus accumbens[6] and prefrontal cortex regions.

[6] Recent studies, reports on the new source of HFO in the olfactory bulb structures, which is surprisingly stronger than any other previously seen in the mammalian brain.

Example of the high-frequency oscillation burst recorded from the brain .
Current source density reconstruction (done with kCSD method, [ 24 ] red and blue dots) of the example HFO burst recorded (6 channel setup - green dots) from rat's brain (grey dots).